We evaluate dark matter ( DM ) limits from cosmic-ray antiproton observations using the recent precise AMS-02 measurements .
We properly take into account cosmic-ray propagation uncertainties , fitting DM and propagation parameters at the same time , and marginalizing over the latter .
We find a significant ( \sim 4.5 \sigma ) indication of a DM signal for DM masses near 80 GeV , with a hadronic annihilation cross-section close to the thermal value , \left \langle \sigma v \right \rangle \approx 3 \times 10 ^ { -26 } cm ^ { 3 } s ^ { -1 } .
Intriguingly , this signal is compatible with the DM interpretation of the Galactic center gamma-ray excess .
Confirmation of the signal will require a more accurate study of the systematic uncertainties , i.e. , the antiproton production cross-section , and the modeling of the effect of solar modulation .
Interpreting the AMS-02 data in terms of upper limits on hadronic DM annihilation , we obtain strong constraints excluding a thermal annihilation cross-section for DM masses below about 50 GeV and in the range between approximately 150 and 500 GeV , even for conservative propagation scenarios .
Except for the range around \sim 80 GeV , our limits are a factor \sim 4 stronger than the limits from gamma-ray observations of dwarf galaxies .